GE MOA 280i, Руководство по эксплуатации и обслуживанию

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GE Analytical Instruments ©2006
16-14
DLM 14291 Rev. A
foaming of the reagent, injection technique and contamination of the samples and
standards.
Syringe Problems
Over time, the needle on the syringe will be etched, particularly by the VCl
3
/HCl
reagent. This results in nitrate contamination of the needle leading to large peaks
even when no sample is injected (needle just inserted in the purge vessel). In
some cases, the needle can be cleaned by placing it in the reagent for a few
minutes, then rinsing with deionized water.
Another problem that is observed is leaks in the plunger or contamination from the
barrel of the syringe. Try using a new syringe to see if this solves repeatability
problems.
Foaming of theVCl
3
Reagent
When samples containing protein are injected, the reagent may foam into the
condenser, cooling the reagent. When the reagent stops foaming and returns to
the heated portion of the purge vessel, residual nitrate will be converted to NO.
The result of this foaming is multiple peaks from a single injection. If multiple
peaks are observed, clean the purge vessel and replace the reagent.
Injection Technique
If the sample is not injected below the liquid level of the reagent, poor
repeatability can be observed as the sample hits the walls of the purge vessel.
Make sure the liquid level is high enough so that the end of the needle is below the
liquid level.
Contamination